Clinical Trial of Cilostazol Eluting Stent System (CES-1) in De Novo Coronary Artery Lesions

Inclusion Criteria: \<Clinical selection criteria\> 1. Patients who have provided written informed consent. 2. Patients who have evidence of myocardial ischemia confirmed by subjective symptoms (chest pain etc.), ST change in the electrocardiogram or objective findings. 3. Patients who are at least 20 years old. \<Angiographic selection criteria\> 1. Single de novo lesion in native coronary arteries 2. Target vessel diameter is 2.75 mm to 3.25 mm. 3. TIMI flow is 2 or more. 4. Angiographic percent diameter stenosis (by visual estimation) is 75% or more in AHA classification Exclusion Criteria: \<Clinical exclusion criteria\> 1. Acute myocardial infarction Patients whose CK-MB or troponin exceeds the facility reference upper limit and have at least one of the following is confirmed are excluded as acute myocardial infarction. * Ischemic symptoms and Electrocardiographic findings showing continuous ischemia (eg, ST segment elevation or depression above 1 mm in contiguous leads, or the appearance of a new left bundle branch block). * Pathological Q waves on electrocardiogram * Myocardial necrotic focus or wall motion abnormality newly confirmed in diagnostic imaging 2. Patients who cannot be given emergency coronary artery bypass grafting (CABG). 3. Patients who cannot be administered antiplatelet drugs. The following cases are conceivable. * Significant intracranial hemorrhage, gastrointestinal bleeding, urinary tract hemorrhage etc. within the last 6 months * Surgical operation is planned that requires discontinuation of DAPT after the procedure * Anticoagulation therapy is underway and the risk of bleeding is high 4. Bleeding tendency due to hemorrhagic diathesis or blood coagulation disorder. 5. Left ventricular ejection fraction (LVEF) is less than 30% within 30 days before the trial registration. 6. Renal dysfunction (Creatinine value exceeds 2.0 mg/dl or in case artificial dialysis). 7. Allergy to cobalt chrome alloy or contrast agent. 8. Patients who are participating in or will planning to participate in other clinical studies that may have clinical implications for the evaluation of this trial. 9. Patients who are pregnant or breast feeding. 10. Patients who are taking Cilostazol. 11. In cases where the Investigator determines that the patient's participation in the trial is inappropriate. \<Angiographic exclusion criteria\> 1. Lesion in left main coronary trunk 2. Lesion within 5 mm from the ostium right coronary artery 3. Lesion within 5 mm from the ostium left anterior descending/the ostium left circumflex branch 4. Bifurcation lesion 5. Within 1 year after implementing PCI on the target vessel or its branch 6. There are other lesions that require PCI at the time of the procedure 7. Type C of ACC / AHA classification